Cal. Code Regs. tit. 4 § 15731

Current through Register 2024 Notice Reg. No. 50, December 13, 2024

Section 15731 - Limits of Detection (LOD) and Limits of Quantitation (LOQ) for Quantitative Analyses

(a) The licensed laboratory shall calculate the LOD for chemical method analyses according to any of the following methods:

(1) Signal-to-noise ratio of between 3:1 and 2:1;

(2) Standard deviation of the response and the slope of calibration curve using a minimum of 7 spiked blank samples calculated as follows; LOD = (3.3 x standard deviation of the response) / slope of the calibration curve; or

(3) A method published by the United States Food and Drug Administration (USFDA) or the United States Environmental Protection Agency (USEPA).

(b) The licensed laboratory shall calculate the LOQ for chemical method analyses according to any of the following methods:

(1) Signal-to-noise ratio of 10:1, at minimum;

(2) Standard deviation of the response and the slope using a minimum of 7 spiked blank samples calculated as follows:

LOQ = (10 x standard deviation of the response) / slope of the calibration curve; or

(3) A method published by the USFDA or the USEPA.

Cal. Code Regs. Tit. 4, § 15731

1. Change without regulatory effect renumbering former title 16, section 5731 to new title 4, section 15731 filed 7-14-2021 pursuant to section 100, title 1, California Code of Regulations (Register 2021, No. 29). For prior history of title 16, division 42, see Register 2019, No. 3.
2. Amendment of subsections (a) and (b) filed 9-27-2021 as an emergency; operative 9-27-2021 (Register 2021, No. 40). This filing is a deemed emergency pursuant to Business and Professions Code sections 26013(b)(3) and 26153.1(k). A Certificate of Compliance must be transmitted to OAL by 3-28-2022 or emergency language will be repealed by operation of law on the following day.
3. Amendment of subsections (a) and (b) refiled 3-28-2022 as an emergency; operative 3-28-2022 (Register 2022, No. 13). This filing is a deemed emergency pursuant to Business and Professions Code sections 26013(b)(3) and 26153.1(k). A Certificate of Compliance must be transmitted to OAL by 9-26-2022 or emergency language will be repealed by operation of law on the following day.
4. Certificate of Compliance as to 3-28-2022 order transmitted to OAL 9-26-2022 and filed 11-7-2022 (Register 2022, No. 45).

Note: Authority cited: Section 26013, Business and Professions Code. Reference: Sections 26100, 26104 and 26110, Business and Professions Code.

1. Change without regulatory effect renumbering former title 16, section 5731 to new title 4, section 15731 filed 7-14-2021 pursuant to section 100, title 1, California Code of Regulations (Register 2021, No. 29). For prior history of title 16, division 42, see Register 2019, No. 3.
2. Amendment of subsections (a) and (b) filed 9-27-2021 as an emergency; operative 9/27/2021 (Register 2021, No. 40). This filing is a deemed emergency pursuant to Business and Professions Code sections 26013(b)(3) and 26153.1(k). A Certificate of Compliance must be transmitted to OAL by 3-28-2022 or emergency language will be repealed by operation of law on the following day.
3. Amendment of subsections (a) and (b) refiled 3-28-2022 as an emergency; operative 3/28/2022 (Register 2022, No. 13). This filing is a deemed emergency pursuant to Business and Professions Code sections 26013(b)(3) and 26153.1(k). A Certificate of Compliance must be transmitted to OAL by 9-26-2022 or emergency language will be repealed by operation of law on the following day.
4. Certificate of Compliance as to 3-28-2022 order transmitted to OAL 9-26-2022 and filed 11/7/2022 (Register 2022, No. 45).